Commit 6ec90cf9 authored Nov 29, 2019 by Zhenhua Huang

mm: arm: Fix BUG() while do iova range checking



This BUG() is triggered when addr + size(like 0x80000000 + 0x80000000)
overflows to 0. It is the implementation only on ARM32.
Hence fix it by decreasing 1 on both sides.
By the way, adding the checking of overflow addr + size to avoid BUG()
in this case.

Change-Id: I1955fa69cd494bdde24f9dbe32879973d65d6fe0
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>

parent 0c4f6840

arch/arm/mm/dma-mapping.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1394,7 +1394,8 @@ static inline void __free_iova(struct dma_iommu_mapping *mapping,

		start = (addr - bitmap_base) >> PAGE_SHIFT;

		if (addr + size > bitmap_base + mapping_size) {
		if ((addr + size - 1 > addr) &&
		(addr + size - 1 > bitmap_base + mapping_size - 1)) {
		/*
		* The address range to be freed reaches into the iova
		* range of the next bitmap. This should not happen as